Shielded relay



SHIELDED RELAY Filed June 5, 1942 3 Sheeswheet 2 July 13, 1943. R. M. HEINTZ.

SHIELDED RELAY 'Filed Jun 5, 1942 s sheets-shew a INVENTOR.

A TTG/@NEX Patented July 13, 1943 UNITED STATES` PATENT OFFICE SHIELDED RELAY Ralph M. Heintz, Cleveland, Ohio, assigner to Jack & Heintz, Inc., Bedford, Ohio, a corporation of Ohio Application June 5, 1942, Serial No. 445,993

(Cl. 20G-87) 8 Claims.

The present invention relates to improvements ln the construction of shielded relays and has particular reference to relays for controlling electric power circuits, such as power circuits for aircraft engine starters and the like.

The object of the invention is to provide an apparent to those skilled in the art as the description proceeds in connection with the accompanying drawings, in which:

Figure 1 is a longitudinal sectional view through a preferred embodiment of the invention, taken approximately on the line I-I in Figure 2;

Figure 2 is a top plan view of the device with the top shell section and top insulating body removed;

Figure 3 is a View of the device inlend elevation;

Figure 4 is an exploded view showing the various parts in partial section;

Figure 5 is a perspective View of the device with the metallic shell sections removed; and

Figure 6 is a perspective View of the device completely assembled.

The relay of the present invention comprises, in general, the following major components: a metallic shell section I, a complementary metallic shell section 2, a main insulating body 3,

a complementary insulating body 4, and the solenoid 5 and associated switch mechanism. It will be seen from the various views in the drawings that the terminal connections and all the switch mechanism are carried by the main insulating body 3, Athe complementary insulating body 4 forming a cover for these parts. The shell sections I and 2 constitute a shielding box protecting the device from mechanical injury and furnishing a means of support for the operating mechanism. In the present embodiment the shell sections are formed of a li'rhtweivht. nonmagnetic metal, but a magnetic metal may be used if desired. The insulating bodies 3 and 4 are preferably formed of a mouldable articial resin or the like, but other classes of insulating materia-1s may be used.

The solenoid 5 is contained within metallic casing elements 6 and I seated in a recess 6b -and having abutting flanges Ea and la seating on four metallic ferrules 8 imbedded in the main body 3. The ierrules 8 are internally threaded at both ends to receive screws 9 securing the said elements 5, 6 and 1, and screws I0 securing the body 4. The solenoid 5 contains a fixed core element II and a movable core element, or plunger, I2, biased upwardly as viewed in Fig. 1 by means of the compression spring Ila. The plunger I2 extends through an opening I2a in the body 3 and carries a post I3 imbedded in ine sulating material I4, and the said post carries.

a circular contact disc I5 thereon. The contact disc I5. is capable of rotation, rocking and axial movements on the post I3, but is urged into `alignment with a iiat shoulder I6 by means of the spring I'I which is retained by a split cup washer I8 snapped into a groove I'Sl. A plurality of projections 20 on the body member 4 form a stop to limit the travel of the contact disc I5 in its 'circuit opening movement under the influence of spring Ila.

Upon energization of the solenoid, the plunger I2 draws the contact disc I5 into bridging engagement with two semi-circular stationary contact segments 2I and 22 secured to the ilat face 23 of the body member 3 by means of the screws 24 and 24a. These screws engage internally threaded ferrules 24h imbedded in the body 3, the large screws 24 serving as terminal posts for power cable lugs 25 which are thereby clamped in contact with the segments 2l and 22. The complementary grooves 25 and 2l in the respective bodies 3 and 4 provide access for relatively heavy power cables, not shown. Smaller terminal screws 28 for lugs 29 in the solenoid circuit are secured in similar ferrules in the body 3. and complementary grooves 30 and 3l provide access to these terminals. A pair of leads 5a complete the solenoid circuit to the terminals. If desired, provision may be made for grounding one of the leads 5c on the shell section I to obviate the necessity for bringing two solenoid ciru cuit wires into they device. The body 3 is undercut beneath the ends of the contact segments 2l and 22 to form grooves 39 to lengthen the short circuit path between the segments.

The above described terminal connections and Contact elements are covered by the body 4 when the latter is secured in place by the screws I0, the contact surfaces between these two bodies being constituted by the plane faces 23 and 32. The top or outer surface of the body 4 is provided with movable contacts, an insulating body carrying a through grbove or channel 33 to accommodate additional conductors having no connection with the relay.

The shell sections I and 2 abut in the plane of the contacting surfaces 23 and 32, and are secured together by screws 34 passing through lhollow dowels 35 extending from the shell section 2 and received in enlarged bores 35a in the lshell section I.

Thelowels 35 serve to accurately match the two shell sections to obtain registry of screw threaded portions 36 and 31 which are adapted to secure couplings of the type supplied on flexible conduit or the like. To

' obtain access to the terminal connections 24 and 28, and to the contact disc I and segments 2| and 22, it is necessary only to unscrew the said couplings and remove the screws 34 and Ill. The shell section 2 and insulating body 4 may then be lifted off to expose thev terminals and operating parts for convenient access on the open surface 23 as shown in Fig. 2, and the remaining assemblage supported by the block 3 may be lifted out of the shell section I if desired. In Fig. 2 the power circuit lugs 25 and the solenoid circuit lugs 29 are shown in place, but the cables to be soldered therein are not shown.,` lHoles 38 vprovide for mounting the shell section I on a suitable support. This support, and the l metallic conduit associated with the shell sections, ordinarily serves to ground the shell to accomplish an electrical shielding effect, it being noted in this connection that the device is completely enclosed by the shell sections I and 2. there being no unshielded conductors to act as antennae for radiating ignition noises and other electrical disturbances which may be picked up by the relay wiring system.

By making the solenoid casing elements 8 and I of magnetic material an external ux path is established to provide a magnetic circuit around and through the solenoid 5, except for the gap between the fixed and movable core elements II and I2 when the latter are separated. This feature is best shown in Figures 1 and 4. When the device is completely assembled the cap I extends through an opening 40 in the shell section I, as shown in Figures 1, 3, and 6.

The exploded view in Figure 4 shows the extent to which the device may be dismantled by merely removing the screws 34 and I0; and Figure 5 illustrates the device with the shell sections I and 2 removed, which is effected by merely removing the screws 34, since the body parts 3 and-4 are not attached to the shell sections. The removal of the shell section 2 permits observation of the\ relay operation through an opening 4I in the cover body 4.

In use, the device is intended to be mounted on a supporting and' grounding structure by means of bolts passing through the holes 38, metallic conductor carrying conduits being secured by means of couplings on the screwthreaded portions 36 and 31. In addition to the solenoid and power circuits, the conduits may contain other conductors trained through the channel 33 and around the boss 42 -surrounding the opening 4I.

The invention is capable of many modifications, and changes, therefore, in the construction and arrangement may be made which do not depart from the spirit and scope of the invention as dei-ined in the appended claims.

I claim:

l. In a shielded relay, an electromagnetic operating mechanism associated with fixed and said mechanism and contacts, a metallic housing shell enclosing said body, a complementary insulating body adapted for union with said first body to cover said mechanism and contacts, and a complementary metallic housing shell enclosing said complementary insulating body and adapted for union with said iirst mentioned housing shell, each of said insulating bodies having semi-cylindrical extensions thereon forming `cylindrical extensions when said bodies are united, terminal connections on the extensions of said first insulating body, and said housing shells having complementary semi-cylindrical threaded extensions -thereon enclosing said cylindrical-.extensions and providing means of attachment for conduit ends carrying cables to saidV terminals.

I union with said rst mentioned housing shell,

2."'In ashielded relay, an electromagnetic operating mechanism associated with xed and `movable contacts, an vinsulating body carrying said mechanism and contacts, terminal connections,` on said body, a metallic housingshell enclosing said body, a complementary insulating body adapted for union with said rst body to cover said mechanism and contacts, and a complementary metallic housing shell enclosing said complementary insulating body and adapted for oppositely directed semi-cylindrical extensions on each of said insulating bodies forming cylindrical extensions when said bodies are united, grooves in said extensions leading to said terminal connections, and a through groove on the f outer surface of said complementary body byplementary metallic housing shell loosely enclosing said complementary insulating body and adapted for union with said iirst mentioned housing shell, said insulating bodies and said shells uniting in a common plane, said plane including said terminal connections.

4. In a shielded relay, a flat-sided insulating body, oppositely directed semi-cylindrical extensions on said body having diametral surfaces lying in the plane of said flat side, terminal connections on said at side, grooves in said diametral surfaces to provide access to said terminals, stationary contacts on said flat sidea solenoid xed in said body, a bridging contact operable by said solenoid, a metallic housing shell enclosing said body and said extensions, a complementary nat-sided insulating body adapted for union with said first body along said plane, a recess and grooves in the flat side of said complementary body to accommodate said bridging contact and terminal connections, stops for said bridging contact in said recess, a continuous groove extending across said complementary body and said extensions thereon, and a complementary metallic housing shell enclosing said complementary insulating body and uniting with said rst-named shell along said plane Ato provide means for connection with conduit ends carrying cables to said terminals.

5. In a shielded relay, an insulating body, an electromagnetic `relay switch carried by said body. terminal connections on said body, a complementary insulating body adapted to unite with said rst 'bocLv to cover said switch and said terminal connections, means to secure said twol bodies together, a metallic housing shell enclos ing said first body, a complementary metallic housing shell loosely enclosing said complementary body, said bodies and said shells uniting in a common plane, screw threaded extensions on said shells intersected by said uniting plane for connection with conduit ends carrying cables to said terminals, hollow dowel means on said shells to register said'screw threads, and securing means for said shells passing through said hollow dowels.

6. In a shielded relay,4 an insulating body, terminal connections on said body, a solenoid seated in said body, a plurality of internally threaded metallic ferrules imbedded in said body,

casing elements of magnetic material enclosing said solenoid and secured to said ferrules, a complementary insulating body covering said terminal connections and secured to said iirst body by means of said ferrules, a metallic shell loosely receiving said nrst body, a complementary metallic shell loosely receiving said complementary insulating body. and means for securing said shells together, said shells and said bodies meeting in a common plane including said terminal connections.

' 7. -An electromagnetic relay comprising'an insulating body, an opening through said body, an annular recess in one side of said body con centric with said opening, a plurality of internally threaded ferrules imbedded in said body around said recess, a solenoid having iixed and movable core elements therein, a pair of casing elements ci magnetic material enclosing said solenoid and providing an external iiux path between said core elements, said casing elements having abutting ilanges, and screws engaging said ilanges and secured in said ferrules to seat said solenoid in said recess with said movable core element operable through said opening,

8. An electromagnetic relay comprising a main insulating body, an opening through said body, an annular recess in one side of said body concentric with said opening, a plurality of internally threaded ferrules imbedded in said body around said recess, a solenoid having xed and movable core elements therein, a pair of casing elements of magnetic material enclosing said solenoid and providing an external ux path between said core elements, said casing elements having abutting flanges, screws engaging said flanges and secured in said i'errules to seat said solenoid in said recess with said movable core element operable through said opening, switch mechanism on the other side oi said body operable .by said movable core element, terminal connections on said other side of said body, a complementary insulating body covering said switch mechanism and terminal connections and screws secured in said ierrules i'or uniting said insulating bodies.

RALPH M. HEINTZ. 

